Telegraph system



Oct. 26, 1937. D. E. BRANSON ET AL 2,096,841

TELEGRAPH SYSTEM Filed Feb. 27, 193.7

Duo-wag SeI ZdiI Line Zine L5 6 Receiving Q ATTORNEY Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE. '1

2,096,841 I TELEGRAPH SYSTEM Application February 27, 1937, Serial No. 128,248

2 Claims.

This invention relates to telegraph systems and more particularly to improved repeater arrangements utilized in such systems.

This application is a continuation in part of a copending application, Serial No. 14,714, filed 'in our names on April 4, 1935.

In the arrangements of this invention the telegraph repeater comprises a plurality of gasfilled discharge tubes and circuit arrangements therefor whereby the. usual magnetic relay arrangements may be eliminated. The arrange ments of the invention accordingly, provide a means for eliminating the expensive maintenance of the electromagnetic type; of relay. The arrangements of the invention furthermore provide a repeater which is more reliable at high speeds than prior arrangements. The repeater arrangements of the invention provide a novel means for interconnecting a two-way line of the polar duplex type to two one-Way lines and also for interconnecting two two-way lines of the polar duplex type together. Other objects and features of the invention will appear more fully from the detailed description thereof hereinafter given.

The invention may be more fully understood from the following description together with the accompanying drawing, in Figures 1 and 2 of which are shown circuit diagrams illustrating an embodiment of the invention and a modification thereof.

In Fig. 1, the repeater arrangements of the invention are shown interconnecting the twoway line L5 with two one-way lines La and L7. The two-Way line L5 may be of thepolar duplex. type and may be connected at its other end to a repeater similar to the one shown or the line may be the open or closed type of loop without a repeater as desired. The two-way line L5 and the two one-way lines L6 and L: are connected together by the double Wheatstone bridge ACDF in a manner similar to a hybrid connection for voice frequency circuits. The sending line La and the receiving line L1 are connected at conjugate points AD and CF so as to prevent signals coming in over line L7 from being repeated back over line Ls. The two-way line L5 is connected to intermediate points BE on the bridge and a balancing network N is connected to the intermediate points B1 E1 in order to preserve the balance of the bridge. The type of. Wheatstone bridge arrangement shown is substantially similar to that illustrated in United States Pat-' ent No. 1,681,216, issued August 21, 1928, to D. E. Branson et a1.

The operation of the arrangements shown in Fig. 1 is as follows: Marking or spacing signals coming in over line L7 will be received. over resistances R13 or R14. A marking signal received over resistance R13 will cause the grid of the gas-' filled discharge tube T3 to be made more positive through potentiometer P1. This will cause the tube T3 to operate and become conductive, thus permittin a direct current to flow over the following path; irombattery B 2, resistance R15, plate of tube T3 to filament of tube T3, to ground. When: the tube T3 becomes conductive, the po:

tential on the plate drops from the full battery 7 potential of battery B22 to the normal sustaining voltage needed to maintain the tube conductive.

When this takes place, the plateof tube T4, which tube was previously conductive, is made suifi-' ciently negative with'respect to its cathode to cause the tube T4 to be extinguished. This is due to the connection of the condenser 04 between the plates of the tubes Ta and T4. This condenser arrangement, whereby the operation of either of the tubes T3 or T4 will cause the release of the other tube, is an arrangement Well' The flow of current over the known in the art. previously traced circuit including battery'Bzz and resistance R15 will apply a marking signal to the line and through the Wheatstone bridge ACDF to the two-way line LS. In a similar manner a spacing signal received over line L7 and resistance R14 will cause the operation of tube T4, the release of tube T3, and the application by means of the circuit including battery B22 and resistance R16 of a spacing signal to the line and then through the Wheatstone bridge ACDF to the two-way line L5. 'Marking or spacing signals coming in over the two-way line L5 will be transmitted over the Wheatstone bridge and will be received over the resistance R11 and R12. A marking signal will be received over resistance R11 and will operate tube T1. This will cause current to fiow from battery B21, through resistance R9, plate and fila-. ment of tube T1, to ground. Due to condenser In Fig. 2 the repeater arrangements of the invention are shown interconnecting two one-way lines L5 and La. As Fig. 2 is in large part similar to Fig. 1 similar reference characters have to be used to denote like parts in both figures. Fig. 2 is identical with Fig. 1 except that the twosomeway lines L6 and L7 are shown connected to the conjugate points D and A and C'and F, respectively of another Wheatstone bridge ACDF'. The second two-way line Ls is shown connected to the intermediate points B and E of the bridge. A balancing network N is connected to the intermediate points B1 and E1. The bridge A'CDF" is identical with the bridge ACDF. As the details of operation of the arrangements are ahe same as those heretofore given with respect to Fig. 1

no further description thereof will be given.

While the inventionhas been described as embodied in certain specific arrangements which are deemed desirable it is understood that it is capable of embodiment in many and other widelyvaried forms without departing from the spirit of the invention as defined by the ap pended claims.

What is claimed is:

1. A telegraph system comprising a two-way line and two one-way'lines, a Wheatstone bridge device, said two one-way lines being connected to conjugate points of said bridge and said two-way line being connectedto intermediate points of said bridge whereby signals coming in over the receiving first of said one-way lines will not be applied to the sending second of said one-way lines, two gas-filled discharge tubes each connected in different sides of said first one-way line, means for causing said tubes to respond altersat en line and two one-way lines, a Wheatstone bridgedevice, said two one-way lines being connected to conjugate points of said bridge and said twoway line being connected to intermediate points of said bridge whereby signals coming in over the receiving first of said one-way lines will not be applied to the sending second of said one-way lines, two gas-filled discharge tubes each con-1 nected in different sides of said first one-way line, means for causing said tubes to respond alternately to marking and spacing signals coming in over said line and to repeat said signals to said two-way line, two gas-filled discharge tubeseach connected in difierent sides of the second of said one-way lines, means for causing said two last mentioned tubes to respond alternately to marking and spacing signals coming in over said two-way line and to repeat such signals over said second one-way line, a second Wheatstone bridge, said two one-way lines being connected to conjugate points of said bridge, and a second two-way line connected to intermediate points of said second bridge.

DAVID E. BRANSON.

WILLIAM H. T. HOLDEN.

JAMES A. EYSTEB. 

